This is indeed correct. If there's a group that is consistently profitable in sports betting, it will likely operate privately, with only a select few people in the know. The fewer people who know, the better it is for them as they can protect their interests. When the general public becomes aware of a particular betting group, bookmakers are more likely to adjust their odds to avoid significant losses, ensuring they still come out on top.

That's why we have what's called 'public bets' and 'sharp bets.' Public bets tend to lose more often, which is why only a few individuals or groups genuinely succeed in gambling.